Rener Gracie has called Punk one of his best students in terms of picking up technique quickly. However, in the same breath, he said that Punk has trained too infrequently for belts to even be in the conversation. We've seen some video of Punk rolling (for those of you not into Jiu-jitsu, training on the mat in the gym). We know he trains with some solid guys: Gracie, and Vinny Magalhes. Just how good is his ground game though?